A fast-moving wildfire that ignited near Spokane Monday is prompting mandatory evacuations, Washington state officials said.

The West Hallett Fire started about 1:30 p.m. about 2.5 miles southwest of Spokane and had high potential for growth, the Washington State Department of Natural Resources said.

At least 20 homes are threatened. Some people in the area were told to evacuate immediately, with others warned to be set to leave, KREM-TV reported.

4 KILLED IN WASHINGTON ATV ACCIDENT AFTER VEHICLE ROLLED OVER, BURST INTO FLAMES

Fourteen planes were dropping water and retardant on the flames, which had burned more than 200 acres by about 5:30 p.m., DNR officials said. No structure loss has been reported, officials said.

The American Red Cross opened a shelter Monday afternoon at Cheney High School.